A train-position detection device disclosed in Patent Literature 1 is constituted by a tachometer-generator that is connected to an axle of a train vehicle, an in-vehicle device that is provided on the train vehicle, and a ground-based device that is provided on the track on which the train vehicle runs. The train-position detection device measures the train position from pulses output by the tachometer-generator in accordance with the rotation of a wheel during running of the train and the diameter of the wheel, but has had a problem in that a measurement error occurs when the wheel slips and skids. In order to correct the measurement error, information of the ground-based device (ID tag) in which position information is pre-stored is read using the in-vehicle device (ID reader), and the measured train position is corrected using the position information read from the ground-based device.
The train-position detection device disclosed in Patent Literature 2 is constituted by an in-vehicle wireless communication apparatus that is provided on the train and a ground-based wireless communication apparatus that is provided by the track of the train. The in-vehicle wireless communication apparatus measures an angle of arrival of a radio wave emitted by the ground-based wireless communication apparatus. Subsequently, the in-vehicle wireless communication apparatus calculates the train position relative to the installation position of the ground-based wireless communication apparatus using the principle of triangulation based on the measured angle of arrival of the radio wave and a distance from the ground-based wireless communication apparatus to the track (hereinafter referred to as a “track distance”).